[logback-dev] svn commit: r2342 - logback/trunk/logback-classic/src/main/java/ch/qos/logback/classic/turbo

[noreply.ceki at qos.ch]

Author: ceki
Date: Sun Jul 12 22:47:09 2009
New Revision: 2342

Added:
   logback/trunk/logback-classic/src/main/java/ch/qos/logback/classic/turbo/ReconfigureOnChangeFilter.java

Log:
- initial very rough implementation of automatic reconfiguration on configuration 
  file change, related to LBCORE-59

Added: logback/trunk/logback-classic/src/main/java/ch/qos/logback/classic/turbo/ReconfigureOnChangeFilter.java
==============================================================================
--- (empty file)
+++ logback/trunk/logback-classic/src/main/java/ch/qos/logback/classic/turbo/ReconfigureOnChangeFilter.java	Sun Jul 12 22:47:09 2009
@@ -0,0 +1,105 @@
+/**
+ * Logback: the generic, reliable, fast and flexible logging framework.
+ * 
+ * Copyright (C) 2000-2009, QOS.ch
+ * 
+ * This library is free software, you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation.
+ */
+package ch.qos.logback.classic.turbo;
+
+import java.io.File;
+import java.net.URL;
+
+import org.slf4j.Marker;
+
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.LoggerContext;
+import ch.qos.logback.classic.joran.JoranConfigurator;
+import ch.qos.logback.core.CoreConstants;
+import ch.qos.logback.core.joran.spi.JoranException;
+import ch.qos.logback.core.spi.FilterReply;
+
+/**
+ * Reconfigure a LoggerContext when the configuration file changes.
+ * 
+ * @author Ceki Gulcu 
+ *  
+ *  */
+public class ReconfigureOnChangeFilter extends TurboFilter {
+
+  final static long DEFAULT_REFRESH_PERIOD = 60*1000; // 1 minute
+  long refreshPeriod = DEFAULT_REFRESH_PERIOD;
+  File fileToScan;
+  protected long nextCheck;
+  long lastModified;
+
+  @Override
+  public void start() {
+    URL url = (URL) context.getObject(CoreConstants.URL_OF_LAST_CONFIGURATION_VIA_JORAN);
+    if(url == null) {
+      fileToScan = convertToFile(url);
+      if(fileToScan != null) {
+        long inSeconds = refreshPeriod/1000;
+        addInfo("Will scan for changes in file ["+fileToScan+"] every "+inSeconds+" seconds");
+        lastModified = fileToScan.lastModified();
+        updateNextCheck(System.currentTimeMillis());
+        super.start();
+      }
+    } else {
+     addError("Could not find URL of file to scan.");
+    }
+  }
+  
+  File convertToFile(URL url) {
+    String protocol = url.getProtocol();
+    if("file".equals(protocol)) {
+      File file = new File(url.getFile());
+      return file;
+    } else {
+      addError("URL ["+url+"] is not of type file");
+      return null;
+    }
+  }
+  
+  @Override
+  public FilterReply decide(Marker marker, Logger logger, Level level, String format, Object[] params, Throwable t) {
+    if(!isStarted()) {
+      return FilterReply.NEUTRAL;
+    }
+    
+    boolean changed = changeDetected();
+    if(changed) {
+      reconfigure();
+    }
+    return FilterReply.NEUTRAL;
+  }
+
+  void updateNextCheck(long now) {
+    nextCheck = now + refreshPeriod;
+  }
+ 
+  protected boolean changeDetected() {
+    long now = System.currentTimeMillis();
+    if(now >= nextCheck) {
+      updateNextCheck(now);
+      return (lastModified != fileToScan.lastModified());
+    }
+    return false;
+  }
+  
+  
+  protected void reconfigure() {
+    JoranConfigurator jc = new JoranConfigurator();
+    jc.setContext(context);
+    LoggerContext lc = (LoggerContext) context;
+    lc.reset();
+    try {
+      jc.doConfigure(fileToScan);
+    } catch (JoranException e) {
+      addError("Failure during reconfiguration", e);
+    }  
+  }
+}